From 8866f405efd4171f9d9c91901d2dd02f01bacb60 Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Tue, 14 Feb 2012 05:18:48 -0500 Subject: ALSA: usb-audio: avoid integer overflow in create_fixed_stream_quirk() A malicious USB device could feed in a large nr_rates value. This would cause the subsequent call to kmemdup() to allocate a smaller buffer than expected, leading to out-of-bounds access. This patch validates the nr_rates value and reuses the limit introduced in commit 4fa0e81b ("ALSA: usb-audio: fix possible hang and overflow in parse_uac2_sample_rate_range()"). Signed-off-by: Xi Wang Signed-off-by: Takashi Iwai --- sound/usb/quirks.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'sound/usb/quirks.c') diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index a3ddac0deffd..27817266867a 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -132,10 +132,14 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip, unsigned *rate_table = NULL; fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL); - if (! fp) { + if (!fp) { snd_printk(KERN_ERR "cannot memdup\n"); return -ENOMEM; } + if (fp->nr_rates > MAX_NR_RATES) { + kfree(fp); + return -EINVAL; + } if (fp->nr_rates > 0) { rate_table = kmemdup(fp->rate_table, sizeof(int) * fp->nr_rates, GFP_KERNEL); -- cgit v1.2.3-55-g7522